Biological and Catalytic Properties of Selenoproteins.
Level 5 - mechanism / opinion, no new human data
Narrative review of biochemical and catalytic mechanisms without human clinical data
PubMed 37373256 · doi:10.3390/ijms241210109
What was done
This narrative review summarizes published literature on the co-translational incorporation, biological roles, and catalytic mechanisms of selenocysteine-containing enzymes in mammals and bacteria.
What was found
The abstract reports no clinical or quantitative trial metrics. It states that 25 selenoprotein genes exist in mammals. Most mammalian selenoenzymes act as antioxidants and redox regulators, whereas selenoprotein P serves as a selenocysteine reservoir. Catalytic mechanisms involve the nucleophilic selenolate form forming Se-X bonds (X = O, S, N, or I) and a selenenylsulfide intermediate recycled by thiol addition. Compared to sulfur, selenium provides faster reaction kinetics and enhanced reversibility of oxidation.
Why it matters
It synthesizes the mechanistic basis for why biological systems utilize selenium rather than sulfur for essential redox regulation and antioxidant protection.
Limits
The abstract describes a non-systematic narrative review with no primary data, quantitative synthesis, or human outcome measurements. It also notes that local and temporal distributions of glutathione peroxidases remain incompletely understood.
Cited by
- supports Several cellular antioxidant enzymes that remove free radicals incorporate selenium into their structure.